Map Function Return

Map function return expects a mapping of arbitrary string keys to values of single element type from function logic. Set values in function logic with a Go map of string keys to values of an appropriate type to match the element type map[string]T or the framework map type.

Function Definition

Use the function.MapReturn type in the function definition.

The ElementType field must be defined, which represents the single framework value type of every element of the map. An element type may itself contain further collection or object types, if necessary.

In this example, a function definition includes a map of string return:

func (f ExampleFunction) Definition(ctx context.Context, req function.DefinitionRequest, resp *function.DefinitionResponse) {
    resp.Definition = function.Definition{
        // ... other Definition fields ...
        Return: function.MapReturn{
            ElementType: types.StringType,
            // ... potentially other MapReturn fields ...
        },
    }
}

Custom Types

You may want to build your own data value and type implementations to allow your provider to combine validation and other behaviors into a reusable bundle. This helps avoid duplication and ensures consistency. These implementations use the CustomType field in the return type.

Refer to Custom Types for further details on creating provider-defined types and values.

Documentation

Return documentation is expected in the top-level function documentation. Refer to function documentation for information about the Summary, Description, and MarkdownDescription fields available.

Setting Return Data

The function implementation documentation covers the general methods for setting function return data in function logic.

When setting the value for this return:

• If CustomType is set, use its associated value type.
• Otherwise, use a Go map of string keys to values of an appropriate type to match the element type map[string]T or framework map type.

In this example, a function defines a map of string return and sets its value:

func (f ExampleFunction) Definition(ctx context.Context, req function.DefinitionRequest, resp *function.DefinitionResponse) {
    resp.Definition = function.Definition{
        // ... other Definition fields ...
        Return: function.MapReturn{
            ElementType: types.StringType,
        },
    }
}

func (f ExampleFunction) Run(ctx context.Context, req function.RunRequest, resp *function.RunResponse) {
    // ... other logic ...

    // hardcoded value for example brevity
    result := map[string]string{
        "key1": "value1",
        "key2": "value2",
    }

    resp.Error = function.ConcatFuncErrors(resp.Error, resp.Result.Set(ctx, &result))
}